This beautiful rhubarb poke cake is a simple 9×13-inch dessert made with a white or yellow cake mix, finely chopped rhubarb, strawberry gelatin, and fluffy whipped topping. The cake bakes in 30–35 minutes, the sweet-tart rhubarb filling takes about 8–12 minutes, and at least 1–2 hours of chilling gives every slice its signature rosy color and moist texture.
Each bite combines tender cake with jammy rhubarb, bright strawberry flavor, and a cool, creamy topping. It is an excellent spring and summer dessert for potlucks, family dinners, birthdays, and any occasion when you want a pretty homemade treat without making a cake from scratch.
Jump to RecipeWhy You’ll Love This Recipe
Rhubarb poke cake has the cheerful look of a bakery dessert but follows a wonderfully practical method. A boxed cake mix provides a dependable tender base, while the cooked rhubarb mixture creates colorful pockets of flavor throughout the cake.
The flavor is balanced rather than overwhelmingly sweet. Rhubarb brings a pleasant tang, sugar softens its sharp edge, strawberry gelatin adds berry flavor and a beautiful pink-red hue, and whipped topping contributes a light, creamy finish.
This dessert is also easy to make ahead. The cake needs at least 1–2 hours in the refrigerator, so it can be prepared earlier on the day you plan to serve it and finished with whipped topping when you are ready to slice.
For another fruit-forward dessert idea, try these strawberry lemon blondies, which pair bright berries with a sunny citrus flavor.
Ingredients You’ll Need
The ingredient list is short, but each component has an important role in the finished cake. Gather the following before you begin:
- One 15.25-ounce box of white or yellow cake mix.
- Three large eggs, 1 cup water, and 1/2 cup vegetable oil for preparing the cake mix.
- Four cups of fresh rhubarb, chopped very small.
- One cup granulated sugar for sweetening the rhubarb.
- One 3-ounce package of strawberry gelatin.
- One cup water, preferably boiling, for the fruit mixture.
- One 8-ounce container of frozen whipped topping, thawed.
White cake makes the rhubarb color especially noticeable, while yellow cake gives the dessert a slightly richer, buttery appearance. Either choice works well, so use the one you enjoy or already have in the pantry.
Choose firm, fresh rhubarb stalks and trim away the leaves before chopping. The stalks should be finely diced so they soften quickly and distribute neatly through the holes in the cake.
If you are planning a dessert table, these mini pumpkin pies also offer individual portions that are easy for guests to pick up and enjoy.
How to Make It Step-by-Step
Step 1: Heat the oven to 350°F and grease a 9×13-inch baking pan, including the corners. Prepare the white or yellow cake mix according to the package directions, using the eggs, water, and vegetable oil listed in the recipe.
Step 2: Pour the batter into the prepared pan and spread it into an even layer. Bake for 30–35 minutes, checking near the end of the baking time; the center should spring back lightly, and a toothpick should come out clean.
Step 3: While the cake is baking, place the finely chopped rhubarb, granulated sugar, and water in a saucepan. Cook over medium heat for 8–12 minutes, stirring now and then, until the rhubarb is very soft and the liquid has become syrupy.
Step 4: Take the saucepan off the heat and immediately stir in the strawberry gelatin. Stir patiently until no dry granules remain and the gelatin is fully dissolved into the warm rhubarb mixture.
Step 5: Remove the cake from the oven and let it cool for about 10 minutes. It should still be slightly warm, but it should not be piping hot when the filling is added.
Step 6: Use the handle of a wooden spoon or a large straw to make holes throughout the cake, spacing them about 1 inch apart. Press straight down and avoid scraping across the surface, since evenly placed holes help the fruit mixture reach the entire cake.
Step 7: Slowly spoon or pour the warm rhubarb-gelatin mixture over the cake. Pause as needed to let it flow into the holes, then spread any remaining filling over the top in a thin layer.
Step 8: Allow the cake to cool completely, then cover the pan and refrigerate it for at least 1–2 hours. Once chilled, spread the thawed whipped topping evenly over the surface just before serving.
Pro Tips for the Best Poke Cake
The best texture comes from timing. Poking a slightly warm cake helps it accept the filling, but pouring the mixture over a piping-hot cake can make the crumb excessively soft, so give it the recommended brief cooling period.
Small rhubarb pieces are important because large chunks may remain firm or block the holes. Aim for a fine chop, and stir the fruit mixture enough to keep the syrup and softened rhubarb evenly combined before pouring.
- Use a pan with straight sides so the cake cuts into tidy squares.
- Make holes about 1 inch apart for consistent filling in every serving.
- Pour slowly instead of flooding the top all at once.
- Chill thoroughly before adding the whipped topping and slicing.
- Use a sharp knife and wipe it between cuts for cleaner portions.
For a neat presentation, spread the whipped topping in gentle swoops rather than pressing it flat. A few tiny pieces of rhubarb on top can hint at the flavor inside without making the cake look busy.
When you want a dessert with a deeper, warmer flavor profile, this chocolate banana bread pudding is another comforting choice for a family-style serving dish.
Serving Suggestions
Serve the cake cold, cut into squares, and keep the whipped topping chilled until the moment it reaches the table. The cool topping contrasts beautifully with the tangy fruit pockets and makes the dessert especially pleasant during warm-weather gatherings.
A simple white plate shows off the pink filling, while a glass baking dish lets guests see the colorful layers before the first slice is served. Add a few thin rhubarb ribbons or a small strawberry beside each piece if you want a more decorative finish.
This cake is sweet enough to stand alone, but it can also be served with fresh berries. For a savory option to balance a dessert spread, consider adding this fresh zucchini noodle salad to the menu.
Storage and Make-Ahead Advice
Cover the finished cake and refrigerate it because the whipped topping and fruit filling are best kept cold. It is most convenient to prepare the cake and filling ahead, chill them completely, and spread on the topping shortly before serving.
For cleanest slices, use a long sharp knife and cut directly down through the chilled cake. If the filling has settled into the holes, that is exactly what you want; those rosy streaks and pockets are part of the charm of a poke cake.
Keep leftovers covered in the refrigerator and serve them cold. Avoid leaving portions at room temperature for extended periods, particularly when serving outdoors or during a warm gathering.
If you are assembling a larger dessert assortment, our pineapple cheesecake cake brings a tropical fruit flavor that pairs nicely with this rhubarb dessert.
Beautiful Rhubarb Poke Cake
Ingredients
Method
- Heat the oven to 350°F and grease a 9x13-inch baking pan. Prepare the cake mix with the 3 eggs, 1 cup water, and 1/2 cup vegetable oil, following the package directions.
- Spread the batter evenly in the prepared pan. Bake for 30–35 minutes, or until the center springs back lightly and a toothpick inserted in the middle comes out clean.
- While the cake bakes, combine the finely chopped rhubarb, sugar, and water in a saucepan. Cook over medium heat for 8–12 minutes, stirring occasionally, until the rhubarb is very soft and the mixture is syrupy.
- Remove the rhubarb mixture from the heat and stir in the strawberry gelatin. Continue stirring until the gelatin has completely dissolved into the warm fruit mixture.
- Let the baked cake cool for about 10 minutes. Use the handle of a wooden spoon or a large straw to poke holes throughout the cake, spacing them about 1 inch apart.
- Slowly spoon or pour the warm rhubarb-gelatin mixture over the cake, pausing so it can seep into the holes. Spread any remaining fruit mixture across the surface.
- Cool the cake completely, cover it, and refrigerate for at least 1–2 hours. Spread the thawed whipped topping over the chilled cake just before serving.
Notes
Final Thoughts
This beautiful rhubarb poke cake is proof that an easy recipe can still look special on the dessert table. The combination of soft cake, syrupy rhubarb, strawberry gelatin, and whipped topping creates a colorful treat with a memorable sweet-tart finish.
Follow the simple timing: bake at 350°F for 30–35 minutes, cook the rhubarb filling for 8–12 minutes, and chill the assembled cake for at least 1–2 hours. Fine chopping, evenly spaced holes, and a gentle pour are the small details that give every slice a moist, flavorful center.
Make it for a spring celebration, a neighborhood potluck, or a casual family meal. Once the first slice reveals its pink filling, this cheerful dessert is sure to become a recipe guests ask you to make again.